Position indicator



Oct. 13, 1953 G. PETERSON, JR

POSITION INDICATOR Filed Oct. 19, 1951 Patented Oct. 13, 1953 omit!) s' et es w 2155 rosrr o v mmcA'roa vGe rg Pete s n Jr S vids .Pa-,a m2 to Riverside MetaYCo'mpany, R verside, N. J., a 'corporationof NeW'Jersey" amp fies? q ber l 1 i1S N 52,1 scam (01. 340-378) This invention relates to electromagnetically operatedpos'ition indicators which are useful in arsm wn One ua i n w ic ma b ii idned but ,only s an exam le t indii cate the up orfdown positionoflanding gear Q al e ed Mer Ra t ub Y the n ntio arelates to an elctromagnetically actuated position indicatorwhe'rein cir uits rEmOtGIY nched and clos d w u e the itiqn indi atq t ak one or another extreme position, or normally to occupy afneutral position when neither of the electromagnetic means is energized.

It'is an object of the invention to provide an s sctroma netic y op at po i d cato which is rugged, compact and may be economically manufactured and assembled from inexpensive" fabricatedparts which are, nevertheless, sturdy andreliable in use.

"Qt'hefr" ject and advantages of the invention will app-ear" as is idesc'i ed in connection with tha ccompanyin Q ia jgs. n' n drawings? ingthe invenucm 2 isaplan viewof the device il lustrated in I .ipartly broken away to illustrate the intei a v a (F-1 3'is allgngitudinalsection view takenalong line;3 3lof-liig. 2'j

' Fig. 4is lafrag'mentarydetail view illustrating the electromagnetic "a'ctuatin means :in one of itslenergizedipositions; gLQS is a perspective view .of vthe armature;

F3ig6 is another detail perspectiveview ofitlhe armature of F 'ig 15,.turned about a vertical axis about one from the positionillustrated in Fig. F v ,v

Fig. is .a schematic diagram of the electrical circuit for the position indicator. Referring to the draw n s; the device is housed een a t mete d e t u a e -l k casing of metaldesignated generallyby the numeral ill. In one end Illa of the casing is a trans-,- parent window 12 through which the position of a movable indicator (designated generally by 39) may be observed. On the opposite end of the casing lflb is mounted a metallic nipple M which is externally screvvthreaded. The nipple may be soldered or otherwise suitably secured to the endlof the casing in air-tight fashion. Through the nipple pass three rod-like conductors l6, l1, and 18 having fingers or prongs, such as I61 I117, extending outwardly to be engaged by lsocket members as 16s and llsof conventional pm; on the ,end of a cable to be secured tolthe nipplebya screwthreaded sleeve I5 in conventional fashion. restless conductors I6, I! and 18 are mutually insulated from one another and spaced apart with their inner ends extending intofthe casing. Wires are soldered uponthe inner ends ofthe conductors I6; I and I8 and are i a t ve Vi w ca emen:

bm qis s h 911 o e lec o asn t so e:

noid's as will hereinaiter be described.

'Preierably all of the operating parts of the device are i ntdn on and S p o t d b a shaped'stamped sheet metal memberdesignated generally'by the numeral 19. The parallel arms lda'an'd [9b (Fig.2) afford support for the operating parts as'will be described in more detail. The transverse portion 19c connecting the arms l9a' and i9b is secured to the end wall lnb of of the casing so that all of the parts may be mounted upon the end wall and, with the end wall, inserted into the casing as a unit.

Riveted to the side arms 19a and [9b directly opposite each other are two electroma'gnet solenoidSiZU and 40, Since these 'electromagnet S016",

noids are identical, only one need be described. Each comprises a spool, such as 22, of molded nylon or other insulation. The axes of the spools are preferably arcuate to receive an arcuate a,r-. mature arm. A toroidal coil, such as 24, is wound around the spool. One of the leads of the coil 25 is connected tothe conductor l6 and one lead of he iL SO nQiQ 5D s conne ed o h 091!- ductorllil. .Theotherleads of each coil are CQlfinected .togetherand to one lead of a resistor R he e h r le d o iej e s s o'r being nn d o.v

conductor IT.

The combined armature and indicator assemhl'y is illustratedbest in Figs. 5 andfi. It comprises anon-magnetic disc member 30 stamped from .thin sheet metal on the opposite sides of whichare mounted armatures 32 and which arelo'fsubstantially Zshape and ofidentical form. nempers a z najaa are stamped from thin sheet metal q aying magneticqualities. Each has a short leg, such as 32b, lying upon and secured to the face of the .disc 30, but on opposite sides thereof and at diametrically opposite positions. Each has an .arcuate long arm, such as 32a, spaced from but adjacent the periphery of the disc and extending in opposite directions towards eachfother but, as previously stated, on opposite sides of the disc. The ends of the long arcuate arms 32a and 3 3a terminate at a distance from each othersubstantially equal to'the length of the spool of the electromagnet solenoid so as to permit the assembly ofth combined indicator and armature member by the pa sageof one of thearms 3 za'abcveand the other 34a below the electromagnet solenoids. Mounted around substantially oneehal'f of the periphery of the disc 31) is a stampedsheetmetal indicator member 39 of arcuate form and having a slight transverse curvatureIwhich adds some stiffness to the otherwise very flexible sheet metal of which the indicator member is made. Preferably the indicator member is made of non-metallic material. It issecured to the disc 30 by lugs or tabs 39t bent downto li uponopposite sides of the surface at diametrically opposite points on the disc 30. These points may beon opposite sides of the disc from the short arms (e. g. 32b) of the armature members 32 and 34 so that rivets or other securing means may serve the common purpose of attaching both the armature members and the indicator member to the disc 30. Preferably the indicator member has in its central portion an indication of the neutral or off position designated generally as 3911. and at either end portion an indication of one extreme or the other extreme position, such as "up and down when the device is used for indication of the position of the landing wheels of aircraft.

In order to pivotally mount the combined armature and indicator member, axial pivot pins 36, 36 are located at the center of the disc 30 to be received within bearing bolts 38 screwed into apertures in the ends of the arms I9a and lSb in alignment, the ends of the screws 38 having conventional conical seats for the pivot pins.

In order to maintain the indicator and armature member in normally neutral position wherein the portion 391i is opposite the window [2, a coiled helical spring 56 is provided having one end turned laterally into a small anchoring hold perforated in the disc 30 and the other end anchored to one of the arms such as [917 of the frame [9 or to an anchor lug 52 a illustrated in Fig. 2, such anchoring lug being fixedly secured to the arm 19b at adjacent the pivot bearing screw 38.

In order that the indicator-armature unit shall be dynamically and statically balanced a portion 39 of the disc 39 may be stamped out to compensate for the added weight of the armature members.

By reference to Fig. '7 typical circuit connections may be observed wherein the switch 54 closes when the wheels of the aircraft are up causing energization of the solenoid coil 40 through the source of current and resistor R. When the wheels are lowered, the switch 56 is closed and the switch 54 opens thus causing energization of the coil in a similar fashion. When neither of the switches is energized the centering spring 59 will cause the armature to take a neutral or off position as illustrated in Fig. 3. Upon energization of either coil, the armature (see Fig. 4) will enter into its coil causin rotation of the armature-indicator member and moving the indicator to show either the up or the down signal indication and thus advise the observer of the existing condition.

Since the disc is non-magnetic as well as the indicator member and since the solenoid coils 20 and are separated and have the disc 30- between them the coils are entirely separate so that the electromagnetic paths of the two solenoids and their armatures are entirely electromagnetically separate and unaffected one by the other.

From the foregoing, it will be observed that my position indicator may be manufactured mainly from stamped sheet metal parts which are relatively thin and inexpensive and may be easily worked and secured together, the lightweight and accurate balancing of the parts makin the device very little susceptible to vibration and improper or accidental operation, and thus very reliable in operation under adverse conditions.

While a particular embodiment of the present invention has been illustrated and described herein, it is not intended to limit the invention to such a disclosure and changes and modifications may be incorporated and embodied therein within the scope of the following claims.

I claim:

1. A unitary electromagnetically operated indicating device comprising a frame stamped from non-magnetic sheet metal and having parallel arms, a solenoid coil mounted on the inner surface of each arm in opposite positions with their cores in parallel, a pivoted indicator and armature unit rotatably mounted adjacent the solenoids about an axis parallel thereto and comprising a rotary disc member of non-magnetic material, armature members mounted on opposite sides of said disc member, each having an arcuate arm portion adapted to enter one of said solenoid cores, said arcuate arm portions terminating at a distance substantially equal to the coil length, an indicator member mounted on the periphery of said disc member and movin with the disc member into two energized positions from a neutral center position, and a centering spring anchored to a frame arm and biasing said disc member in central position.

2. A device as claimed in claim 1, wherein the indicator member has tabs at diametrically opposite positions lying on opposite sides of the disc member, said armature members having portions adjacent said tabs but on opposite sides of the disc member, and securing means passing through said tabs and opposite armature portions jointly securing the indicator and armature members to the disc.

3. A device as claimed in claim 1, wherein said disc member moves in a plane between said solenoid coils and afiords a magnetic barrier between them adjacent the armature arms.

4. A device as claimed in claim 1, wherein said frame, disc, indicator and armature members are thin sheet metal.

5. An electromagnetically operated indicating device comprising a housing having a window therein, an indicator movable to show a plurality of positions of said indicator through said window, a supporting frame carrying all operating parts of said device, a wall of said housing supporting said frame whereby the frame and wall, as a unit, may be assembled in the housing, said frame having parallel arms, a pair of electromagnetic solenoid coils mounted opposite each other on the inside surfaces of said arms with their cores substantially parallel, an indicator. and armature assembly comprisin a disc of non-. magnetic material, an armature secured on each side of said disc each having an arcuate arm adapted to enter the core of one of said solenoids on energization of the solenoid, means pivotally mounting said armature-indicator assembly between said frame arms with said disc moving in a plane between said solenoids, and a centering spring moving said indicator-armature assembly into a midposition when neither of said solenoids is energized.

GEORGE PETERSON, JR.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,022,742 Kellum Apr. 9, 1912 1,285,371 Powell Nov. 19, 1918 2,223,678 Elliott Dec. 30, 1940 2,405,429 Jewell Aug. 6, 1946 FOREIGN PATENTS Number Country Date 3,172 Great Britain Feb. 9, 1906 515,515 Great Britain Dec. 7, 1939 

